2 files changed, 25 insertions, 0 deletions
diff --git a/src/multimedia/audio/qaudiooutput_win32_p.cpp b/src/multimedia/audio/qaudiooutput_win32_p.cpp
index 72e772482..7592643f4 100644
--- a/src/multimedia/audio/qaudiooutput_win32_p.cpp
+++ b/src/multimedia/audio/qaudiooutput_win32_p.cpp
@@ -117,6 +117,7 @@ QAudioOutputPrivate::QAudioOutputPrivate(const QByteArray &device)
     audioSource = 0;
     pullMode = true;
     finished = false;
+    volumeCache = (qreal)1.;
 }
 
 QAudioOutputPrivate::~QAudioOutputPrivate()
@@ -380,6 +381,8 @@ bool QAudioOutputPrivate::open()
     timeStampOpened.restart();
     elapsedTimeOffset = 0;
 
+    setVolume(volumeCache);
+
     errorState = QAudio::NoError;
     if(pullMode) {
         deviceState = QAudio::ActiveState;
@@ -667,6 +670,25 @@ QAudio::State QAudioOutputPrivate::state() const
     return deviceState;
 }
 
+void QAudioOutputPrivate::setVolume(qreal v)
+{
+    const qreal normalizedVolume = qBound(qreal(0.0), v, qreal(1.0));
+    if (deviceState != QAudio::ActiveState) {
+        volumeCache = normalizedVolume;
+        return;
+    }
+    const qint16 scaled = normalizedVolume * 0xFFFF;
+    DWORD vol = MAKELONG(scaled, scaled);
+    MMRESULT res = waveOutSetVolume(hWaveOut, vol);
+    if (res == MMSYSERR_NOERROR)
+        volumeCache = normalizedVolume;
+}
+
+qreal QAudioOutputPrivate::volume() const
+{
+    return volumeCache;
+}
+
 void QAudioOutputPrivate::reset()
 {
     close();
diff --git a/src/multimedia/audio/qaudiooutput_win32_p.h b/src/multimedia/audio/qaudiooutput_win32_p.h
index a5a4852de..064ca89c0 100644
--- a/src/multimedia/audio/qaudiooutput_win32_p.h
+++ b/src/multimedia/audio/qaudiooutput_win32_p.h
@@ -112,6 +112,8 @@ public:
     qint64 elapsedUSecs() const;
     QAudio::Error error() const;
     QAudio::State state() const;
+    void setVolume(qreal);
+    qreal volume() const;
 
     QIODevice* audioSource;
     QAudioFormat settings;
@@ -134,6 +136,7 @@ private:
     qint64 totalTimeValue;
     bool pullMode;
     int intervalTime;
+    qreal volumeCache;
     static void QT_WIN_CALLBACK waveOutProc( HWAVEOUT hWaveOut, UINT uMsg,
             DWORD dwInstance, DWORD dwParam1, DWORD dwParam2 );